Q: How to overcome the activation required iphone5

I got crazy with my 2 iphone 4 coz after factory reset i can not use anymore  because it only stocks on HELLO. If going to connect itunes with sim it will only displays sim card not accepted and when theres is no sim it requires a sim to be inserted. And my iphone 5 if i will not put a sim i can use it for internet using wifi BUT if i put a sim it requires activation and authorization. I can not open and use it coz it only stock on. It dsplays the bar signal but i can not activate it using wifi or      Itunes. Since i am new in the world of ios pls guys help me coz it really drives me crazy.